With regard to broadcasts across systems, while it may not be ideal- there has to be a suspension of disbelief in a RP game at any level. If I have time, I'll focus attention on a single vessel. 'Republican Shipping vessel Phaethon to the Donaghue. Get out of the way you damn dock hog.' For example.
I don't like restricting my RP to private channels and groups, RP should be seen by everyone involved (everyone in system) in my view, so they have the opportunity to react and interact.
With regard to not seeing the faces of people, we see the faces of npcs all the time when they talk to us through comms. We all have webcams in our cockpits, obviously.